Authentication of meat species and net muscle proteins: updating of an old concept

The aim of the study was to develop an efficient method for assessment of meat origin and determination of net muscle protein (NMP; based on amino acids and β-alanylhistidine dipeptides) in meat products using the ultra-high performance liquid chromatography coupled with mass spectrometry. As an important result, a database of ratios of particular amino acids to 3-metylhistidine, applicable for muscle protein origin confirmation, was established. Based on the specific ratios of 1-methylhisitidine/3-methylhistidine, revealing of undeclared addition of 2% of chicken meat to the pork was enabled. Similar outcome was achieved by considering the ratios of β-alanylhistidine dipeptides. In the case of chicken-pork and pork-beef admixtures, as low additions as 0.5 and 2% of chicken or pork adulterant could be recognized. The ratio of 4-hydroxyproline/3-methylhisitidine was shown to be diagnostic for detection undeclared addition of 0.5 and 1.5% of connective tissues into the pork and chicken meat, respectively. On the basis of 3-methylhisitidine concentration, the conversion factor F = 292 ± 4 was calculated for quantification of NMP (%) content.

Application of soy protein isolate in the fining of red wine

Soy protein isolate was evaluated as a potential fining agent as an alternative to the predominant protein commercial fining agents (ovalbumin, porcine gelatin, and pea protein isolate). Two red wines (cv. ‘Merlot’ and cv. ‘Lambrusco Maestri’) were finned, bottled, and analyzed for phenolic content, color, turbidity, and sensory profile. Independent of the protein used, fining promoted a reduction in a majority of the phenolic compound, a slight (but significant) reduction of chromatic properties, and a decrease in the turbidity of the wines. A decrease in astringency, persistence, bitterness, and wine body, as well as an increase in brightness, clarity, and acidity, was also observed in all treatments. The application of soy protein isolates yielded similar results to those obtained with other commercial fining agents, both in the physicochemical and the sensory measures, which favors its usage as an alternative to the traditional fining agents of animal-protein origin.

Manganese Ions Complexation Processes with Organic and Inorganic Compounds and their Migration in a Low-flowing Water Body Ecosystem

Processes of metal ions complexation in a water system containing hydrogen carbonate ions and sulphate ions, as well as dead off supreme aquatic vegetation organic matter and organic compounds of protein origin have been considered. Complexation processes’ interconnection with manganese ions migration in a low-flowing water body has been justified.

Traditional and Modern Protective Media for the Low-Temperature Bacteria Preservation

Presented are the literature data on the efficiency of bacteria preservation at temperatures ranging from -20 to -196 °C in the protective media containing such cryoprotectors as glycerol, dimethyl sulfoxide, carbo-hydrates, substances of protein origin specified by regulatory guidelines. Most of the focus is on the publications reporting the results of the long-term bacteria preservation at sub-zero temperatures, optimization of the protective media for pathogenic bacteria, and usage of the compounds with potential cryoprotective activity. Noted is the necessity for approbation of the specified protective media for the conserved bacteria species at the applied preserving temperatures. One of the approaches to the enhancement of the low-temperature preservation techniques is a search for natural protectors, which can provide for surviving of bacteria in the unfavorable conditions, including low temperatures, and a search for possibility to integrate these natural protectors into the cryoprotective media. Displayed are the results of effective application of glycerol-betaine, and polysaccharides of Arctic microorganisms for the low-temperature bacteria preservation.